YCbCr

Y’CbCr is a component video system which represents RGB colour space in a bandwidth-efficient form for storage and transmission, it is not a colour space of its own.

The CbCr plane given a constant Y’ of 0.50

Y’ refers to the the LUMA component of the signal, Cb to the difference between the LUMA and the blue component, Cr to the difference between the LUMA and the red component.

The system requires processing power in order to convert the RGB colour space into Y’CbCr for storage or transmission, and back for display. However, the system lends itself to far more efficient transmission by allowing available bandwidth to be concentrated on the most critical component in terms of visual information, the LUMA, while reducing that allocated to the colour components or by utilising compression, subsampling or other means.

There is no need for a green difference component as this can be calculated by taking the LUMA component and removing the blue and red components given by the difference data Cb and Cr.